Acetylsalicylic acid

Acetylsalicylic acid (Brand names: Aspirin, Aspro, Aspegic, Alka Seltzer, Aspirin Cardio, cardioaspirine, Cardiopirin, Cardipirin, among others) is a nonsteroidal antiinflammatory drug (NSAID) used for treating pain, fever, arthritis and other types of inflammation. Acetylsalicylic acid may also be used to reduce the risk of heart attack.

Acetylsalicylic acid inhibits irreversibly the enzyme, cyclooxygenase (COX), an early component of the arachidonic acid cascade, resulting in the reduced formation of prostaglandins and thromboxanes. Prostaglandins act as messenger molecules in the process of inflammation.

Low doses of Acetylsalicylic acid block platelet production of thromboxane A2 and thereby, platelet activation and aggregation. This property accounts for its use in the long-term prevention of heart attacks. The inhibitory effect of Acetylsalicylic acid on platelet thromboxane production persists for the lifespan of the platelet, around 7 to 10 days. As a result, acetylation of platelet cyclooxygenase and consequent inhibition of thromboxane formation is cumulative on repeated dosing.

Prevention of Complications of Pregnancy: Pregnancy-induced hypertension, Preeclampsia, Intrauterine growth retardation. Aspirin, is also used together with heparin in pregnant women with antiphospholipid syndrome, an autoimmune, hypercoagulable state caused by antiphospholipid antibodies. APS provokes blood clots as well as pregnancy-related complications such as miscarriage, stillbirth, preterm delivery, and severe preeclampsia.

Risk of Bleeding: The chance is higher in patients age 60 or older, have had stomach ulcers or bleeding problems, taking a blood thinning (anticoagulant) or steroid drug, taking other drugs containing prescription or nonprescription NSAIDs (Ibuprofen, Naproxen, or others), having 3 or more alcoholic drinks every day while using Acetylsalicylic acid or taking more or for longer than directed. Avoid Acetylsalicylic acid use one week prior to and during labor, delivery, and any surgical procedure because it can result in excessive blood loss.

Acetazolamide: Increased serum acetazolamide concentrations and toxicity due to competition at the renal tubule for secretion

Anticoagulant therapy (Heparin, Warfarin): Increased risk of bleeding because of drug-drug interactions and the effect on platelets

Anticonvulsants: Salicylate can displace protein-bound phenytoin and valproic acid, leading to decreased total concentration of phenytoin and increased serum valproic acid levels

Beta-blockers: Diminished hypotensive effects of beta-blockers due to inhibition of renal prostaglandins, leading to decreased renal blood flow, and salt and fluid retention

Diuretics: Diminished effectiveness of diuretics in patients with underlying renal or cardiovascular disease due to inhibition of renal prostaglandins, leading to decreased renal blood flow and salt and fluid retention

Methotrexate: Salicylate may inhibit renal clearance of methotrexate, leading to bone marrow toxicity, especially in the elderly or renal impaired

Severe bleedings such as cerebral bleeding, particularly in patients with non-stabilised hypertension and/or concomitant treatment with anticoagulants, which in isolated cases could be life-threatening

Gastrointestinal bleeding which in very rare cases can lead to iron deficiency anemia. Signs are black stools or vomit blood.

Gastrointestinal ulcers which in very rare cases can lead to perforation

Hypersensitivity reactions of the respiratory system ,gastrointestinal tract and of the cardiovascular system, particular in asthmatics. The following symptoms may occur: a drop in blood pressure, attacks of difficult breathing, rhinitis, nasal congestion, allergic shock, swelling of the face, tongue and larynx (angioedema)

Manifestation
These include dizziness, tinnitus, sweating, nausea, vomiting, and altered glucose metabolism, mental confusion, and hyperventilation, respiratory alkalosis, metabolic acidosis, and ketosis, fluid and electrolyte losses. Depression of the central nervous system may lead to coma, cardiovascular collapse and respiratory failure.
In children serious signs of over dosage may develop rapidly. In cases of over dosage, consult a doctor immediately.